Nervous system Part 3 Flashcards
what are the 3 subsystems of somatosensory
- cutaneous mechanoreceptor
- proprioception
- pain and temperature
where does mechanosensory information from the upper body enter?
cervical spinal cord - cuneate tract, crosses over contra laterally
where does mechanosensory information from the lower body enter?
lumbar spinal cord- gracile tract, crosses over contralaterally
first synapse of the mechanosensory pathway?
caudal medulla
second synapse of mechanosensory pathway?
ventral posterior lateral thalamic nuclei
two types of proprioceptors?
- muscle spindle- muscle length changes
2. Golgi tendon organ- tension on muscle
muscle spindle groups
group 1a - movement of limbs, rapidly adapting
group 2- static limb position, slowly adapting
nociceptors
receptors that sense pain
A/sigma fiber group
fast pain pathway, intense mechanical or thermal
ex. hitting hand with a hammer
- first pain felt
C fiber group
slow pain pathway, thermal mechanical or chemical
- second pain felt
how are pain signals transducer?
TRPV1 and TRPV2 receptors that flux Na and Ca
which pathway does pain/temp follow?
anterolateral pathway
what are the 3 branches of the autonomic nervous system
- sympathetic (fight/flight)
- parasympathetic (rest/digest)
- enteric
mechanisms for regulating autonomic pathway?
- antagonistic actions: opposite affects
- dual innervention: input from both systems
- basal tone
where do the neurons of the parasympathetic system originate?
close to the target organs (cranial nerves and sacrum)
